Prognostic Impact of Trial-Eligibility Criteria in Patients with Metastatic Renal Cell Carcinoma

Objective: The aim of the study was to evaluate the prognostic impact of trial-eligibility criteria on outcome in real-world metastatic renal cell carcinoma (mRCC) patients treated with tyrosine kinase inhibitors (TKIs). Patients and Methods: mRCC patients treated with TKIs as first-line systemic therapy were retrospectively evaluated. The patients were determined as trial-ineligible when they met at least 1 following trial-ineligible criteria; Karnofsky performance status score <70, hemoglobin <9.0 g/dL, creatinine >2.4 mg/dL (male) or >2.0 mg/dL (female), calcium >12.0 mg/dL, platelet <100,000 /mu L, neutrophil <1,500 /mu L, nonclear-cell histology, and brain metastasis. Results: Of 238 patients, 101 patients (42%) were determined as trial-ineligible. Progression-free survival (PFS) and overall survival (OS) after the TKI initiation were significantly shorter in the trial-ineligible patients than in the trial-eligible patients (median PFS: 5.53 vs. 15.8 months, p < 0.0001; OS: 13.8 vs. 43.4 months, p < 0.0001). Objective response rate was also significantly lower in the trial-ineligible patients (15% vs. 37%, p = 0.0003). Multivariate analysis further showed that the trial-eligibility was an independent factor for PFS (hazard ratio [HR]: 2.46, p < 0.0001) and OS (HR: 2.39, p < 0.0001). In addition, the number of trial-ineligible factors were negatively correlated with PFS and OS. Conclusions: In real-word, the substantial number of mRCC patients did not meet the trial-eligibility criteria, and their outcome was worse than that in the trial-eligible patients. Further studies focusing on the outcome in real-world trial-ineligible patients in the immune checkpoint inhibitor era are warranted.